Postulating that therapeutic intervention increasing the involvement of the father in parenting would help in treating adolescent borderlines, Anderson has required that fathers (not mothers) be treated concurrently (not conjointly) with the adolescent by the same therapist. He has found this extremely helpful and gives two clinical examples illustrating the advantages and some of the difficulties of this technique. He then reviews the theoretical concept that the presence of an empathic father ("an external object which can survive apart from the mother") is crucially important in the resolution of the separation-individuation